choices, one on top of another
...this early stage that parents can begin to accustom the child to the art of making choices. Let him do many things, in his own rhythm, for in “puttering” he may be engaged in valuable experimentation, that is, making bridges in the sandpile or piling blocks one on top of another, or he may be...
Nash would use the word “puttering” in a pejorative sense in a later (1960) publication. See putterings 127 for that instance, and for links to more info about this prolific writer and authority on parks and recreation.
See also the volume Nash edited, Recreation, pertinent readings : guide posts to the future (1965), borrowable at archive.org : link. The book is largely concerned with the challenges of “leisure.”